In message <20050115151907.GA9021@spathi.chuq.com>, Chuck Silvers writes:
>hi,

>
>
>> -I now believe that the best way to deal with this would be to
>>  have UBC reads just return zero filled pages if the file is
>>  not backed with real data, and let upper layers (above the
>>  trap handler) check whether the read is legal. Just commenting
>>  out the range check in genfs_getpages() isn't enough,
>>  unfortunately. That's a pretty complex matter...
>
>creating pages for offsets past EOF is to be avoided in general, since
>it's pretty nonsensical.  I checked in a different fix for this issue,
>update uvm_bio.c.
>

I don't understand -- are you trying to bar files with holes in them?  
That's been part of Unix since the beginning.

		--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb